/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.jobmanager.scheduler;

import org.apache.flink.util.AbstractID;

import java.util.Objects;

import static org.apache.flink.util.Preconditions.checkNotNull;

/**
 * A read-only and light weight version of {@link CoLocationConstraint}.
 */
public class CoLocationConstraintDesc {

	private final AbstractID coLocationGroupId;

	private final int constraintIndex;

	CoLocationConstraintDesc(final AbstractID coLocationGroupId, final int constraintIndex) {
		this.coLocationGroupId = checkNotNull(coLocationGroupId);
		this.constraintIndex = constraintIndex;
	}

	@Override
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		} else if (obj != null && obj.getClass() == getClass()) {
			CoLocationConstraintDesc that = (CoLocationConstraintDesc) obj;
			return Objects.equals(that.coLocationGroupId, this.coLocationGroupId) &&
				that.constraintIndex == this.constraintIndex;
		} else {
			return false;
		}
	}

	@Override
	public int hashCode() {
		return 31 * coLocationGroupId.hashCode() + constraintIndex;
	}
}
